(1) Technical Field of the Invention
The present invention relates to a method for checking the dimensions of patterns, more particularly to a method by which it can be easily determined whether or not the minute patterns formed on a semiconductor wafer satisfy a predetermined standardized dimensional requirement.
(2) Description of the Related Art
The circuit patterns of a semiconductor integrated circuit must be accurately formed to guarantee the high quality thereof, and therefore, the patterns are checked at each process in the production of the semiconductor products.
In the conventional pattern checking method, first, an operator discriminates patterns having a predetermined shape, and to be checked, from various kinds of patterns formed on a wafer. The sampled patterns are then displayed on a monitoring display wherein the dimensions of the patterns are measured against a scale and judged to be acceptable or unacceptable.
Today, IC's are integrated at a much higher density than before, and thus the circuit patterns are becoming more minute. Therefore, it is not only difficult to measure and check the size of the pattern but also difficult to discriminate and sample the pattern to be checked, having a predetermined shape, from the various and many kinds of patterns formed on the wafer or the mask.
In the conventional checking method, patterns are displayed in a monitor device and an operator first discriminates the pattern to be checked from the displayed patterns and then checks the dimension of the pattern against a scale. Such a checking operation is time-consuming and difficult, and the reliability of checking is not satisfactory.